EYA4 mRNA level in ICC tissues was significantly lower than that in adjacent non-tumorous tissues, with a median ΔCt of 13.14 (range, 8.45–17.03) vs 11.77 (range, 7.38–14.87; P < 0.001; Fig. 1a). This evidence concerns the gene EYA4 and intrahepatic cholangiocarcinoma.